A replay attack is a form of network attack in which a data transmission via, for example, hypertext transfer protocol (HTTP) requests are repeated or delayed, typically in a malicious manner. A replay attack may occur when an attacker copies a stream of messages between two parties and replays the stream to one or more of the parties. In the case of, for example, a web application that lets users upload data to a backend server, a large amount of data may be transmitted across the network as an HTTP upload request. The request may be captured as it traverses the system (e.g., traverses the network, servers, and the like the request may be resent any number of times. In some cases, a user may maliciously resend the request in an attack on the infrastructure. Unless mitigated, the computers subject to the attack may process the stream as legitimate messages, resulting in a range of consequences, such as redundant orders of an item. For example, if a server inserts data into a database table in response to the maliciously resent requests, the database may grow and may eventually be filled up with data from the replayed requests. In this situation, the server may fail.